1. Field of the Invention
The present invention relates generally to cooling modules for automotive applications. More particularly, the present invention relates to cooling modules having airflow by-pass features.
2. Disclosure Information
Cooling modules used in automotive applications typically consist of a condenser, auxiliary heat exchangers, an engine cooling fan, and a radiator. Ambient air from the surrounding environment travels through the cooling module, whereupon the engine is cooled by the action of the radiator, and climate control of an enclosed space can be provided by the action of the condenser in conjunction with other known air conditioning system components.
Because the cooling module is enclosed, the same amount of air must flow through both the radiator and the condenser. Thus if the airflow required by the radiator and the condenser to satisfy the need for engine cooling and climate control respectively are different from one another, the engine cooling fan must provide for the greater airflow requirement. If these two requirements for airflow differ greatly, the efficiency of the cooling module could decrease dramatically. Airflow through each heat exchanger, the radiator and condenser, not only sees the pressure drop associated with that heat exchanger, but also the pressure drop associated with the other heat exchanger. In most applications, the radiator is positioned downstream of the condenser. Thus, the air which flows through the radiator is not at ambient temperature, as it has already been heated by the condenser. The radiator and condenser also provide resistance to the airflow drawn by the cooling fan, thus the cooling fan requires greater energy to overcome this resistance. Because of all of these effects, there is an inherent drop in efficiency associated with having the radiator and condenser positioned in-line with one another, as the cooling fan must consume more power. The operation of the cooling fan then becomes louder.
Prior art devices have overcome the problem of this decrease in efficiency by having two heat exchangers in separate airstreams. The inventors of the present invention have found disadvantages with the prior approach. For example, not only does this approach require the use of two fans rather that one, thereby increasing the production cost, but it also forces the cooling module to occupy more space. In order for such an approach to occupy the same amount of space as the conventional approach of placing the condenser and radiator in-line with one another, the core face area of each heat exchanger would need to be cut in half. This decrease in core face area would also result in a decrease in heat exchange. Concerns regarding cost and space, such as the limited space under a hood in an automotive application of a cooling module, dictate that the condenser and radiator be placed in line with one another.